Imaging data (e.g., digital images, depth images or other sets of data) typically includes a collection of image pixels, arranged in an array corresponding to a frame, which defines an optically formed reproduction of one or more objects, backgrounds or other features of a scene. For example, in a digital image, each of the pixels represents or identifies a color or other light condition associated with a portion of such objects, backgrounds or features. A black-and-white digital image includes a single bit for representing a light condition of a pixel in a binary fashion (e.g., either black or white), while a grayscale digital image may represent the light condition in multiple bits (e.g., two to eight bits for defining tones of gray in terms of percentages or shares of black-and-white), and a color digital image may include groups of bits corresponding to each of a plurality of base colors (e.g., red, green or blue), with the groups of bits collectively representing a color associated with the pixel. In a depth image, each of the image pixels represents or identifies not a light condition or color of such objects, backgrounds or features, but a distance to objects, backgrounds or features. For example, a pixel of a depth image may represent a distance between an imaging sensor of an imaging device (e.g., a depth camera or range sensor) that captured the depth image and the respective object, background or feature to which the pixel corresponds. Other imaging data (e.g., infrared images, or radiographic images) may include image pixels having values corresponding to variables other than color or distance, such as heat or radiation.
Presently, there are two primary techniques for operating (or “shuttering”) an imaging device such as a digital camera, a range camera, an infrared camera, a radiographic camera or the like to capture imaging data. Global shuttering (or, simply, “global shutter”) is a method in which each of the pixel sensors provided on an imaging sensor, e.g., a photosensitive surface, is exposed and processed simultaneously. The pixel sensors are exposed for a finite and common period of time, called an “exposure time,” defined by a shutter speed for the imaging sensor. When this period of time has elapsed, e.g., after each of the pixel sensors has been exposed, analog signals generated by the exposure of the entire array of pixel sensors in an imaging area (known as a “frame”) are converted to digital signals, in series. Some imaging sensors that operate according to global shutter methods typically include charge-coupled devices (or CCD) or like components.
Rolling shuttering (or, simply, “rolling shutter”) is a method in which a plurality of pixel sensors provided on an imaging sensor, e.g., a photosensitive surface, is exposed and processed in a rolling fashion, such as row-by-row or column-by-column, across multiple rows or columns of pixels in an imaging area, and not simultaneously. Thus, a rolling shutter method exposes pixel sensors on different portions of the imaging area at different points in time, and for common periods of time (e.g., exposure times), before converting analog signals generated by pixel sensors in a common row or column into digital signals. The points in time at which the pixel sensors of a common row or column are exposed may differ by fractions of seconds. Some image sensors that operate according to rolling shutter methods typically include complementary metal oxide semiconductor (or CMOS) chips or like components.
Global shutter methods are advantageous because each of the pixel sensors is exposed, and analog signals captured by such sensors is processed, at a common time. However, due to the fact that each of the analog signals of a frame must be converted to digital signals before any of the pixel sensors may be exposed again, global shutter methods are often subject to congestion or bottlenecking, and must therefore operate with comparatively lower frame rates. Conversely, rolling shutter methods are advantageous because such methods may operate with higher frame rates, and because each row or column of pixel sensors within a frame may, once the analog signals captured by the pixel sensors within the row or column are converted to digital signals, be subjected to exposure again and subsequently processed. However, the processing of pixel sensors on a row-by-row or column-by-column basis naturally introduces a time delay between the processing of respective or adjacent rows or columns, which may result in blurring or other spatial distortions in the imaging data captured using such pixel sensors.